Ammonia is a compound of hydrogen and nitrogen with the chemical formula NH3. In commercial applications, ammonia is often provided as anhydrous ammonia, which simply means that the ammonia is not dissolved in water, or as part of a different compound, such as ammonium nitrate or urea. The main uses of ammonia are in the production of fertilizers, explosives and polymers. Because of its many uses, there are dozens of chemical plants worldwide that produce ammonia. The United States Geological Survey estimates that worldwide ammonia production in 2004 was 109 million metric tonnes. The People's Republic of China produced 28.4% of the worldwide production, followed by India with 8.6%, Russia with 8.4%, and the United States with 8.2%. About 80% or more of the ammonia produced is used for fertilizing agricultural crops.
Recently, ammonia has been suggested as a substitute for carbon based fuel sources, such as gasoline, diesel fuel, natural gas, and coal. Numerous potential benefits might be achieved by using ammonia as a fuel. For example, previous studies such as G. Marnellos, S. Zisekas, M. Stoukides, “Synthesis of Ammonia at Atmospheric Pressure with the Use of Solid State Proton Conductors,” Journal of Catalysis, 193, 80 (2000) have described the electrocatalytic solid-state synthesis of ammonia starting from hydrogen and nitrogen gases. Numerous studies under the United States Department of Energy Hydrogen Program have also investigated the solid-state electrolysis of steam for the production of hydrogen. J. S. Herring, J. E. O'Brien, C. M. Stoots, K. DeWall, M. McKellar, E. Harvego, M. Sohal, G. L. Hawkes, and R. Jones, “Laboratory Scale High Temperature Electrolysis System”, DOE Hydrogen Program FY 2006 Progress Report, page 173 and I. I. Balachov, S. Crouch-Baker, M. Hornbostel, M. McKubre, A. Sanjurjo, and F. Tanzella, “Modular System for Hydrogen Generation and Oxygen Recovery”, DOE Hydrogen Program FY 2006 Progress Report, page 363. Unfortunately, these approaches have not been shown to be economically viable when compared to traditional methods of ammonia production, principally as a result of the cost of the energy used to form hydrogen from water. Still, since nitrogen is available from the atmosphere, and hydrogen is available in water, ammonia can theoretically be produced anywhere on earth. Using ammonia as a substitute for petroleum based energy sources could therefore, in theory, lessen the dependence on foreign countries to supply energy, provided that more efficient production methods were found.
Since burning ammonia does not produce carbon dioxide, using ammonia as a fuel source also has potential benefits to the environment. Unfortunately, however, current technologies for commercial scale ammonia production do not rely on water and air as inputs. Instead, these commercial facilities generally consume significant quantities of carbon based fuels, thereby counteracting at least some of the potential benefits that could be achieved by using ammonia as a fuel.
Modern ammonia-producing plants typically utilize some variation of the Haber-Bosch process to produce ammonia from the nitrogen contained in the air. The process, developed by Fritz Haber and Carl Bosch in 1909 and patented in 1910, first converts carbonaceous chemical feed stocks, such as natural gas, (methane), coal, liquified petroleum gas (propane and butane), or petroleum naphtha, into gaseous hydrogen. Catalytic steam reforming is then used to form hydrogen plus carbon monoxide, for example in steam reforming of methane:CH4+H2O→CO+3H2 
The next step then uses catalytic shift conversion to convert the carbon monoxide to carbon dioxide and more hydrogen:CO+H2O→CO2+H2 
To produce the desired end-product ammonia, the hydrogen is then catalytically reacted with nitrogen (derived from process air) to form anhydrous liquid ammonia.3H2+N2→2NH3 
In modern ammonia plants using the Haber-Bosch process, a variety of other steps are also typically performed, such as removing sulfur from the carbonaceous feed stock. Typically, the energy necessary to perform all of these operations is provided by burning the carbonaceous fuels, typically natural gas. As a result, modern ammonia production facilities typically create massive amounts of carbon dioxide, because they are producing carbon dioxide from the burning of carbon based fuels to provide both the energy and hydrogen necessary to promote the Haber-Bosch and related processes. As a result of the widespread use of these prior art methods, while ammonia is the fifth most abundantly produced chemical in the United States, it ranks number two on the list of chemicals requiring the most energy to produce, according to estimates from the United States Department of Energy. Most, if not all, of the carbon dioxide produced in world-wide ammonia production is ultimately vented to the atmosphere.
Over the course of the past two decades, a consensus has emerged among the global scientific community that carbon dioxide in the atmosphere has the unfortunate effect of allowing sunlight to pass through and warm the earth's surface, but then traps the radiant energy created by that warming, and preventing it from escaping through the earth's atmosphere back into space. There is also a general consensus among scientists that this condition, generally termed the “greenhouse effect,” is gradually raising the average temperature of the earth's atmosphere and oceans, which in turn is creating highly detrimental consequences, including but not limited to, raising sea levels at or near highly populated coastal regions, and unusually severe weather, droughts, floods, tornadoes, storms, hurricanes and typhoons, and the like. It has been estimated that the costs of global warming caused by the greenhouse effect will eventually run into the trillions of dollars, and some commentators believe that unless global warming is somehow reversed, it will ultimately result in the deaths of billions of people throughout the world.
Accordingly, there exists a need for new energy sources, such as ammonia, that do not generate so-called “greenhouse gasses” such as carbon dioxide, when they are burned. There is a further need for new sources of energy, such as ammonia, which may be produced domestically, to lessen the dependence on foreign suppliers. Finally, even if the use of ammonia as a fuel is ignored, there is still a need for new methods of producing ammonia for use as fertilizer that do not require carbon based fuels as energy sources and/or as the hydrogen source, as is typical in the Haber-Bosch process. The present invention addresses all of these needs simultaneously.